Self-grounding connector for joining end sections of fluid flow conduits and fabrication processes therefor

ABSTRACT

An electrically self-grounding connector for joining end portions of fluid flow conduit sections, and two processes for fabricating the connector. A connector formed according to one process includes an inner layer formed by electrically conductive, contiguous carbon ribbons, an outer layer of chopped carbon fibers, and a layer of surfacing veil between the inner and outer layers. A connector formed according to the other process substitutes a layer of carbon cloth for the carbon ribbons. In both connectors, electrically conductive carbon forming the inner and outer surfaces acts to dissipate and neutralize electrostatic charges generated by triboelectric processes.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of application Ser.No. 09/882,683 filed Jun. 18, 2001 and published as Ser. No.2002/0017333 A1, entitled “Electrostatic Charge Neutralizing Fume DuctWith Continuous Carbon Fiber,” now pending.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to gas and fluid flow conduits suchas ductwork, and more particularly to a self-grounding connector forjoining end portions of conduit sections. The connector includes carbonfibers which dissipate and neutralize built-up electrostatic chargesresulting from triboelectric processes as vapors, gases or liquids flowthrough a conduit.

[0004] 2. Description of the Related Art

[0005] Published application Ser. No. 2002/0017333 A1 (“'333”), which isincorporated in its entirety herein by reference, discloses aself-grounding dual-wall duct for transporting corrosive vapors andgases, and a process for fabricating such ducts and pipe. The duct has alaminated inner wall whose innermost layer incorporates continuous,helically-wound carbon filament ribbons which dissipate and neutralizebuilt-up electrostatic charges resulting from vapor or gas flow. The'333 reference further discloses a joint assembly providing highelectrical conductivity, and thereby self-grounding, across the joint.The assembly includes a self-grounding collar for joining twodual-laminate duct sections. The collar has a laminate constructionincluding two relatively thin inner layers of carbon filament ribbonimpregnated with an epoxy or any other type of chemically resistantvinyl ester resin-and-curing agent admixture, and a relatively thickouter layer of glass filament ribbon impregnated with the admixture. Theassembly further includes a sealant having chopped carbonized carbonfibers. The filament layers provide self-grounding of the collar innersurface, and the fibers provide self-grounding of the collar outersurface.

[0006] Pat. No. 6,315,004 (“'004”) to R. L. Wellman et al., which isincorporated in its entirety herein by reference, discloses a laminatedinner wall of a dual-wall fume duct for transporting corrosive vaporsand gases, and a process for fabricating the wall. The innermost layerof the wall is made of a cured epoxy or any other type of chemicallyresistant vinyl ester resin incorporating chopped carbonized carbonfibers.

OBJECTS OF THE INVENTION

[0007] It is a primary object of the present invention to provide animproved connector impermeable to hazardous gases, vapors and fluids,and which dissipates and neutralizes electrostatic charge build-up onits inner and outer surfaces.

[0008] Another object of the invention is to provide a self-groundingconnector fabricated using a substantially automated production processamenable to standardization and high quality control.

[0009] Yet another object of the invention is to provide a simplifiedproduction process using fewer types and lesser amounts of fabricationmaterials per unit connector.

[0010] Other objects of the invention will become evident when thefollowing description is considered with the accompanying drawingfigures. In the figures and description, numerals indicate the variousfeatures of the invention, like numerals referring to like featuresthroughout both the drawings and description.

SUMMARY OF THE INVENTION

[0011] These and other objects are achieved by the present inventionwhich in a first aspect provides a self-grounding connector for joiningend portions of fluid flow conduit sections. The connector includes ahollow resinous body incorporating a highly electrically conductivematerial which dissipates and self-grounds electrostatic chargeaccumulating on the inner and outer surfaces. In a first embodimentcarbon fiber filaments ground the inner surface, and chopped carbonfibers ground the outer surface. In a second embodiment carbon clothgrounds the inner surface, and chopped carbon fibers ground the outersurface.

[0012] In another aspect the invention provides a process for making aself-grounding connector for joining end portions of fluid flow conduitsections. The steps include: (a) covering a mandrel with a non-stickingmaterial; (b) forming over the material a layer using a conductivematerial and a fluidic admixture; (c) forming over the layer a secondlayer using a second conductive material and the admixture; and (d)removing the formed layers from the mandrel to form the connector.

[0013] In yet another aspect the invention provides a first process formaking a self-grounding connector for joining end portions of fluid flowconduit sections. The process steps include: (a) forming a fluidicadmixture of a settable chemically resistant resin and a curing agent;(b) coating a non-sticking sheeting covering a mandrel with a layer ofthe admixture; (c) helically winding around the sheeting a band formedby contiguous, continuous electrically conductive ribbons havingcontinuous carbon filaments impregnated with the admixture, therebyforming a ribbon-layer embedded in the admixture layer; (d) coating theribbon-layer with a second admixture layer; (e) helically winding alayer of surfacing veil wetted out with the admixture; (f) coating theveil with a third admixture layer; (g) depositing chopped carbon fibersto cover the veil; (h) integrating the fibers and admixture to form alayer of wetted out fibers terminating in a smooth outer surface; and(i) orthogonally winding a second band having at least one ribbonimpregnated with the admixture, thereby forming a circumferential bead.

[0014] In still another aspect the invention provides a second processfor making a self-grounding connector for joining end portions of fluidflow conduit sections. The process steps include: (a) forming a fluidicadmixture of a settable chemically resistant resin and a curing agent;(b) coating a non-sticking sheeting covering a mandrel with a firstlayer of the admixture; (c) helically winding around the sheeting alayer of carbon cloth wetted out with the admixture; (d) curing theadmixture layer and wetted out cloth; (e) covering the cloth with alayer of putty; (f) helically winding into the putty a layer ofsurfacing veil; (g) curing the putty; (h) coating the veil with a secondlayer of the admixture; (i) depositing chopped carbon fibers to coverthe veil; (j) integrating the fibers and admixture to form a layer ofwetted out fibers terminating in a smooth outer surface; and (k)orthogonally winding a second band having at least one ribbonimpregnated with the admixture, thereby forming a circumferential bead.

[0015] A more complete understanding of the present invention and otherobjects, aspects and advantages thereof will be gained from aconsideration of the following description of the preferred embodimentsread in conjunction with the accompanying drawings provided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a perspective view of a self-grounding connectoraccording to the invention, including a circumferential bead.

[0017]FIG. 2A is a schematic cross-sectional view of the FIG. 1connector fabricated according to a first process embodiment.

[0018]FIG. 2B is a schematic cross-sectional view of the FIG. 1connector fabricated according to a second process embodiment.

[0019]FIG. 3 schematically shows a first step in making a FIG. 2A orFIG. 2B connector wherein a thin coating of an admixture of a settablechemically resistant resin and a curing agent therefor is rolled onto anon-sticking sheeting covering a rotating mandrel.

[0020]FIG. 4 schematically shows a second step in making the FIG. 2Aconnector wherein continuous, contiguous carbon fiber-filament ribbons,after transiting a bath containing the FIG. 3 admixture, are helicallywound around the sheeting until its surface is totally covered with asingle ribbon-layer, as hereinafter defined.

[0021]FIG. 5 schematically shows a second step in making the FIG. 2Bconnector wherein a layer of carbon cloth wetted out with the FIG. 3admixture is helically wound around the FIG. 3 sheeting.

[0022]FIG. 6A schematically shows a third step in making the FIG. 2Aconnector wherein a second thin coating of the FIG. 3 admixture isapplied to the outer surface formed by the FIG. 4 contiguous ribbons andtrapped air is rolled out with a roller.

[0023]FIG. 6B shows a third step in making the FIG. 2B connector whereina thin coating of putty is applied to the outer surface of the FIG. 5carbon cloth after it has cured.

[0024]FIG. 7A schematically shows a fourth step in making the FIG. 2Aconnector wherein a layer of surfacing veil, wetted out with the FIG. 3admixture, is helically wound into the FIG. 6A admixture coating.

[0025]FIG. 7B shows a fourth step in making the FIG. 2B connectorwherein a layer of surfacing veil is helically wound into the still-softFIG. 6B putty, which is then cured.

[0026]FIG. 8 shows a fifth step in making the FIG. 2A or FIG. 2Bconnector wherein, respectively, a third or second, thin coating of theFIG. 3 admixture is applied to the veil outer surface.

[0027]FIG. 9 schematically shows a sixth step in making the FIG. 2A orFIG. 2B connector wherein a layer of chopped carbonized carbon fibers isdeposited onto and into the layer of FIG. 3 admixture covering the FIG.8 veil outer surface.

[0028]FIG. 10 schematically shows a seventh step in making the FIG. 2Aor FIG. 2B connector wherein a roller is used to smooth out the FIG. 9fibers.

[0029]FIG. 11 schematically shows an eighth step in making the FIG. 2Aor FIG. 2B connector wherein continuous, contiguous carbonfiber-filament ribbons, after transiting a bath containing FIG. 3admixture, are orthogonally wound around the FIG. 10 surface to form acircumferential bead.

[0030]FIG. 12 schematically shows how several FIG. 2A or FIG. 2Bconnectors are successively made by forming a plurality of FIG. 10 beadsspaced along the mandrel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] I. Introduction

[0032] While the present invention is open to various modifications andalternative constructions, the preferred embodiment shown in thedrawings will be described herein in detail. It is to be understood,however, there is no intention to limit the invention to the particularforms disclosed. On the contrary, it is intended that the inventioncover all modifications, equivalences and alternative constructionsfalling within the spirit and scope of the invention as expressed in theappended claims.

[0033] II. Connector with Carbon Fiber-Filament Inner Wall

[0034]FIGS. 3, 4, 6A, 7A, 8, 9, 10 and 11 show sequential steps infabricating a self-grounding connector 20A according to a firstembodiment of the invention, as shown in FIGS. 1 and 2A. Referring toFIG. 3, in a first step a sheeting 22 made of a non-sticking materialand covering a slowly rotating, generally circular mandrel 24 is evenlycoated using a fiberglass applicator roller 26 with a thin layer 28 of aliquid admixture 30 of a settable chemically resistant resin, eitherhalogenated or unhalogenated, and a curing agent therefor. Preferablythese are, respectively, an epoxy vinyl ester impregnating resin andbenzoyl peroxide. Preferably, the sheeting is a polyester film such asMYLAR®. Other materials which can be used include: (a) fluoropolymerfilms such as HALAR® ethylene trichlorofluoroethylene copolymer andKYNAR® (poly)vinylidene fluoride; (b) polyolefin films such aspolypropylene film; (c) other polyester films; and (d) metallic foilssuch as wax coated aluminum foil. Alternatively, a cardboard tube isinterposed between the mandrel and sheeting to further facilitateremoval of the finished cylindrical product from the mandrel. Layer 28has an interior surface 28S contiguous to the sheeting 22 and anexterior surface 28E. Layer 28 is 2 to 3 mils in thickness and isdispensed from a suitable dispensing device 32. The benzoyl peroxide,which is 1 to 5 percent-by-weight relative to the weight of the resin,cures the liquid resin to a solid at ambient temperature. About 0.3pound of resin per square foot of mandrel surface area is used.Preferably, the resin is type 510A-40 DERAKANE® manufactured by the DowChemical Company of Channahon, Ill.

[0035] Mandrel 24 is clamped generally horizontally between a rotatingchuck and a tailstock spindle of a filament winding machine, and rotatesat a selectable constant rate. As detailed in the '333 publishedapplication, a two-axis machine is used to apply a matrix of carbonfibers and resin under controlled tension to the mandrel in apredetermined geometrical pattern. As shown schematically in FIG. 4, ina second step a plurality of continuous carbon fiber-filament ribbons ishelically wound onto the mandrel after passage through a bath 34containing the admixture 30. In a preferred embodiment eight ribbons,each about 0.250-inch in width and about 0.010-inch in thickness, afterunwinding from contiguous spools S1, S2, S3, S4, S5, S6, S7, S8 andexiting bath 34, are aligned edge-to-edge by a payout eye 36 to form atwo-inch wide band 38. The band is wound helically onto surface 28E atan angle of about 72° with respect to the mandrel's longitudinal axis toform a diamond-shaped pattern. As the eye moves back and forth along themandrel, interstices in the pattern are filled in to form a singlecontinuous ribbon-layer 40 (see FIG. 6A). Ribbon-layer 40 is embedded inadmixture layer 28 so that interior surface 28S is integrated with asmooth continuous surface 40S (see FIG. 2A) of resin-impregnated carbonfiber-filaments which preferably is about 63 percent carbon and 37percent admixture, by weight, within a feasible range of about 50 to 70percent carbon and about 30 to 50 percent admixture. Typically, thethickness of ribbon-layer 40 is about 25 mils, but can be between 15 and35 mils. Alternatively, a lesser or greater number of ribbons may beused to provide a narrower or wider bandwidth. Preferably, the ribbonused is PANEX® 33-48K continuous carbon fiber which has a filament countof 45,700 and a yield of 450 ft/lb, manufactured from polyacrylonitrile(PAN) precursor by Zoltek Corporation of St. Louis, Mo.

[0036] Referring to FIG. 6A, in a third step ribbon-layer 40 is evenlycoated with a thin layer 42 of admixture 30, and a fiberglass “deairing”roller 44 is used to roll out air trapped in the ribbon-layer. Layer 42typically is 2-3 mils in thickness.

[0037] Referring to FIG. 7A, in a fourth step a layer 50 of surfacingveil having an outer surface 50S, about 10 mils in thickness and wettedout with the admixture 30, is helically wound over layer 42. Typically,the veil width is about 4 inches. Preferably, glass “C”-veil is used.C-veil is glass fiber tissue of randomly dispersed glass fibers bondedinto a sheet by a polyester resin. The fibers are produced from “C”glass, a chemically resistant glass highly resistant to attack by bothacid and alkaline environments. C-veil is available commercially fromOwens Corning Corp.

[0038] Referring to FIG. 8, in a fifth step surface 50S is evenly coatedwith a thin layer 46 of liquid admixture 30. Preferably, the thicknessof layer 46 is about 10 mils. Referring to FIG. 9, in a sixth step amultiplicity of quarter-inch length chopped carbon fibers 52 are evenlyapplied onto and into layer 46 as the mandrel rotates. The fibers aremanufactured by heating, oxidizing and carbonizing PAN fibers.Preferably, the fibers are PANEX® 33-CF, manufactured by ZoltekCorporation, which have a diameter of 0.283 mil, a density of 0.065lb/in³, and an electrical resistivity of 0.00068 ohm-inch. Preferably,the fibers 52 are sprayed on using a chop-gun 54 such as manufactured byVenus-Gusmer Inc. of Kent, Wash. Alternatively, the fibers may beapplied by hand. Referring to FIG. 10, in a seventh step a deairingroller 56 is used to break down any clumps of fibers and blend thefibers with admixture 30, resulting in a homogeneous layer 58 of fibersand admixture having a thickness of about 10 mils and a generally smoothouter surface 58S.

[0039] Referring to FIG. 11, in an eighth step a plurality of continuouscarbon fiber-filament ribbons, aligned edge-to-edge by a stationarypayout eye 60 to form a band 64 of a preselected width, are orthogonallywound around surface 58S after passage through a bath 62 containingadmixture 30. Sufficient ribbon-layers are formed to create acircumferential bead 66 having a height in a range from 0.187- to0.250-inch. FIG. 11 schematically shows four ribbons unwinding fromcontiguous spools R1, R2, R3, R4. The number of spools and the ribbonwidth used in a particular manufacturing run depend on the bead widthdesired. FIG. 12 schematically shows that after a bead is completed thepayout eye is moved a preselected distance along the mandrel and anotherbead is formed. After curing the resultant carbon-glass-carboncylindrical tube at ambient temperature and sliding it off the mandrel,a plurality of beaded connectors C1, C2, C3, . . . are produced bysuccessively sawing off transverse segments each having a beadequidistant between its ends. Alternatively, sawing may be done with thetube still on the mandrel.

[0040] Paragraph 0041 and FIG. 9 of the '333 application disclose acollar used in a joint assembly to connect the end portions of two fumeduct sections. The same technique is employed in using theself-grounding connectors of the present invention to connect the endportions of two conduit sections.

[0041] III. Connector with Carbon Cloth Inner Wall

[0042]FIGS. 3, 5, 6B, 7B, 8, 9, 10 and 11 show sequential steps infabricating a self-grounding connector 20B according to a secondembodiment of the invention, as shown in FIGS. 1 and 2B. The first,fifth, sixth, seventh and eighth steps are identical, respectively, tothe first, fifth, sixth, seventh and eighth steps used in fabricatingconnector 20A. So only the second, third and fourth steps are describedbelow.

[0043] Referring to FIG. 5, in a second step a single layer 70 of carboncloth having an interior surface 70S and an exterior surface 70E, wettedout with the admixture 30, is wound helically onto layer 28, and thenallowed to cure at ambient temperature. The cured resin fills theinterstices of the porous cloth to form an impermeable barrier.Preferably, the cloth is carbon “boat” cloth about 10 mils in thickness,available commercially from Zoltek Corporation.

[0044] Referring to FIG. 6B, in a third step a thin layer 72 of putty 73is dispensed from a dispensing device 74 onto surface 70E. Preferably,the thickness of layer 72 is about 10 mils. Preferably, the putty is anadmixture including vinyl ester resin and benzoyl peroxide curing agent,chopped carbon fibers in a percentage-by-weight of 1 to 20 percent, andfumed silica in a percentage-by-weight of 3 to 10 percent.Alternatively, the putty is an admixture including epoxy resin and aminecuring agent, chopped carbon fibers in a percentage-by-weight of 1 to 20percent, and fumed silica in a percentage-by-weight of 3 to 10 percent.

[0045] Referring to FIG. 7B, in a fourth step a layer 76 of surfacingveil having an outer surface 76S is wound into the still-soft putty.Preferably, the veil is glass C-veil about 10 mils in thickness. Beforeproceeding to the fifth step wherein surface 76S is evenly coated with athin layer of liquid admixture 30, the putty is allowed to cure.

[0046] IV. Resistivity Test Results

[0047] A. Test Method

[0048] Volume and surface resistivity tests according to ASTM D 4496-87were performed on specimens cut from a connector having fabricatedaccording to the first process embodiment of the present invention. Theconnector was approximately 6 -inches in diameter by 3.5-inches wide by0.070-inch thick. The tests were performed by Delsen TestingLaboratories, Inc. of Glendale, Calif. Five specimens, eachapproximately 3.5-inches by 1-inch, were cut out from the axialdirection of the connector. The specimens were cleaned with isopropylalcohol and distilled water and dried at room ambient conditions. Afour-point measurement technique was used to determine the resistance ofthe specimens. Two ends of each specimen were painted with conductivesilver paint and served as current electrodes. Two conductive silverpaint lines were applied across the width of the inner surface of eachspecimen and served as potential electrodes. While DC current wasapplied to the specimen through the two outer electrodes, the potentialdrop between the two inner electrodes was measured.

[0049] Resistance was calculated as follows:

R=V/I

[0050] where R=resistance (ohms); V=potential drop (volts); I=appliedcurrrent (amperes).

[0051] Volume and surface resistivity were calculated as follows:

ρ_(V)=((2.54×t×W)/L)×R

ρ_(S)=(W/L)×R

[0052] where

[0053] ρ_(V)=volume resistivity (ohm-cm)

[0054] ρ_(S)=surface resistivity (ohms/square)

[0055] R=resistance (ohms)

[0056] t=specimen thickness (inches)

[0057] L=distance between potential electrodes (inches)

[0058] W=specimen width (inches)

[0059] B. Test Results

[0060] All tests were performed at 73° F. temperature and 35% relativehumidity. Table 1 shows the resistances measured on each of the fivespecimens, and the calculated volume and surface resistivities. In allcases the measured resistance was extremely low. TABLE 1 VOLUME ANDSURFACE RESISTIVITY TEST METHOD: ASTM D 4496-87 (Reapproved 1998)ELECTRODE TYPE: Conductive silver paint TEST CONDITIONS: Tested at 73°F. and 35% R.H. DISTANCE BETWEEN SPECIMEN SPECIMEN POTENTIAL VOLUMESURFACE CURRENT WIDTH THICKNESS ELECTRODE RESISTANCE RESISTIVITYRESISTIVITY DIRECTION inches inches inches ohms ohm-cm ohms/squareSpecimen No. 1 Forward 1.00 0.070 1.98 10.72 0.96 5.4 Reverse 1.00 0.0701.98 10.73 0.96 5.4 Specimen No. 2 Forward 1.01 0.070 1.97 9.46 0.86 4.9Reverse 1.01 0.070 1.97 9.47 0.86 4.9 Specimen No. 3 Forward 0.99 0.0701.98 9.46 0.84 4.7 Reverse 0.99 0.070 1.98 9.46 0.84 4.7 Specimen No. 4Forward 1.01 0.070 1.97 6.79 0.62 3.5 Reverse 1.01 0.070 1.97 6.79 0.623.5 Specimen No. 5 Forward 1.01 0.070 1.97 9.30 0.85 4.8 Reverse 1.010.070 1.97 9.30 0.85 4.8

What is claimed is:
 1. A self-grounding connector for joining endportions of fluid flow conduit sections, said connector comprising: ahollow resinous body having inner and outer surfaces determining apreselected thickness, and incorporating highly electrically conductivefirst and second materials which dissipate and self-ground electrostaticcharge accumulating, respectively, on said inner and outer surfaces. 2.The connector of claim 1 wherein said first material comprises at leastone carbon ribbon having a multiplicity of carbon fiber-filaments. 3.The connector of claim 2 wherein each ribbon is helically disposedwithin said resinous body.
 4. The connector of claim 3 wherein eachcarbon ribbon has been saturated with an admixture of a settablechemically resistant resin and a curing agent therefor.
 5. The connectorof claim 1 wherein said first material comprises carbon cloth.
 6. Theconnector of claim 5 wherein said cloth has been saturated with anadmixture of a settable chemically resistant resin and a curing agenttherefor.
 7. The connector of claim 4 or 6 wherein said resin is ahalogenated epoxy vinyl ester resin.
 8. The connector of claim 4 or 6wherein said resin is an unhalogenated epoxy vinyl ester resin.
 9. Theconnector of claim 2 or 5 wherein said conductive second materialcomprises a multiplicity of chopped carbon fibers.
 10. The connector ofclaim 9 wherein said fibers are manufactured from polyacrylonitrileprecursor.
 11. The connector of claim 10 wherein said fibers determine alayer of a preselected thickness terminating in said body outer surface.12. The connector of claim 11 wherein a layer of surfacing veil of apreselected thickness underlies and is contiguous to said fibers layer.13. The connector of claim 12 wherein said body outer surface isprovided with a centrally disposed, circumferential highly electricallyconductive bead for aligning thereon end portions of fluid flow conduitsections.
 14. The connector of claim 13 wherein said bead comprises amultiplicity of ribbon-layers of at least one carbon ribbon.
 15. Aprocess for making a self-grounding connector for joining end portionsof fluid flow conduit sections, comprising the steps of: covering amandrel with a non-sticking material; forming over said material a firstlayer using a first conductive material and a fluidic admixture; formingover the first layer a second layer using a second conductive materialand the fluidic admixture; and removing the formed first and secondlayers from the mandrel to form the self-grounding connector.
 16. Theprocess of claim 15 wherein: said first conductive material comprisescarbon filaments; said fluidic admixture comprises a settable chemicallyresistant resin and a curing agent therefor; and said second materialcomprises carbon fibers.
 17. The process of claim 15 wherein: said firstconductive material comprises carbon cloth; said fluidic admixturecomprises a settable chemically resistant resin and a curing agenttherefor; and said second material comprises carbon fibers.
 18. Aprocess for making a self-grounding connector for joining end portionsof fluid flow conduit sections, comprising the steps of: forming afluidic admixture of a settable chemically resistant resin and a curingagent therefor in a preselected percentage-by-weight, relative to theweight of the resin, as a supply source of the same; evenly coating asheeting made of a non-sticking material and covering a generallyhorizontal mandrel with a first layer of said fluidic admixture, saidlayer having an interior surface contiguous to the sheeting and anexterior surface, the interior and exterior surfaces determining apreselected layer thickness, the mandrel symmetric about a longitudinalaxis; helically winding around the sheeting, at a preselected anglerelative to the mandrel longitudinal axis, a carbon band of apreselected width comprising a plurality of electrically conductive,continuous ribbons each having a multiplicity of continuous longitudinalcarbon filaments impregnated with said fluidic admixture, said ribbonshaving a common preselected width determined by opposed generallyparallel edges and a preselected thickness, and disposed contiguouslyedge-to-edge, said carbon band wound in a plurality of helical segmentsforming a ribbon-layer covering and embedded in said first layer of saidfluidic admixture and integrated with said interior surface, saidribbon-layer in a preselected percentage-by-weight relative to theweight of said fluidic admixture; evenly coating said ribbon-layer witha second layer of said fluidic admixture of a preselected thickness,thereby forming an outer surface; helically winding a layer of surfacingveil having an outer surface and a preselected thickness and wetted outwith said fluidic admixture, around said second layer outer surface;evenly coating said veil outer surface with a third layer of saidfluidic admixture of a preselected thickness; depositing a multiplicityof chopped carbon fibers onto and into said third admixture layer,covering said veil outer surface; and integrating said fibers and thirdadmixture layer thereby determining a substantially homogeneous layer ofwetted out fibers of a preselected thickness terminating in a generallysmooth outer surface.
 19. The process of claim 18 wherein: the thicknessof each of said first and second fluidic admixture layers is in a rangefrom 0.002- to 0.003-inch, and the thickness of said third fluidicadmixture layer is about 0.010-inch; said preselected angle is in arange from about 55 to about 72 degrees; the percentage-by-weight ofsaid ribbon-layer is in a range from about 50 to about 70 percent, andthe percentage-by-weight of said first fluidic admixture layer is in arange from about 30 to about 50 percent; the thickness of saidribbon-layer is a range from 0.015- to 0.035-inch; said surfacing veillayer is glass C-veil about 0.010-inch in thickness; and the thicknessof said layer of wetted out carbon fibers is about 0.010-inch.
 20. Aprocess for making a self-grounding connector for joining end portionsof fluid flow conduit sections, comprising the steps of: forming afluidic admixture of a settable chemically resistant resin and a curingagent therefor in a preselected percentage-by-weight, relative to theweight of the resin, as a supply source of the same; evenly coating asheeting made of a non-sticking material and covering a generallyhorizontal mandrel with a first layer of said fluidic admixture, saidlayer having an interior surface contiguous to the sheeting and anexterior surface, the interior and exterior surfaces determining apreselected layer thickness, the mandrel symmetric about a longitudinalaxis; helically winding around the sheeting a layer of carbon clothhaving an outer surface and a preselected thickness and wetted out withsaid fluidic admixture; curing said first admixture layer and wetted outcarbon cloth; covering, to a preselected thickness, said carbon clothouter surface with a layer of putty comprising a settable resin and acuring agent therefor, chopped carbon fibers, and fumed silica;helically winding around the carbon cloth and into the still-soft puttya layer of surfacing veil of a preselected thickness and having an outersurface; curing the putty; evenly coating said veil outer surface with asecond layer of said fluidic admixture of a preselected thickness;depositing a multiplicity of chopped carbon fibers onto and into saidsecond admixture layer, covering said veil outer surface; andintegrating said fibers and second admixture layer thereby determining asubstantially homogeneous layer of wetted out fibers of a preselectedthickness terminating in a generally smooth outer surface.
 21. Theprocess of claim 20 wherein said putty comprises: vinyl ester resin andbenzoyl peroxide curing agent; chopped carbon fibers in apercentage-by-weight range of 1 to 20 percent; and fumed silica in apercentage-by-weight range of 3 to 10 percent.
 22. The process of claim20 wherein said putty comprises: epoxy resin and amine curing agent;chopped carbon fibers in a percentage-by-weight range of 1 to 20percent; and fumed silica in a percentage-by-weight range of 3 to 10percent.
 23. The process of claim 21 or 22 wherein: the thickness ofsaid first fluidic admixture layer is in a range from 0.002- to0.003-inch, and the thickness of said second fluidic admixture layer isabout 0.010 -inch; said carbon cloth is carbon boat cloth having athickness about 0.010 -inch; the thickness of said putty layer is about0.010-inch; said surfacing veil layer is glass C-veil about 0.010-inchin thickness; and the thickness of said carbon fibers layer is about0.010-inch.
 24. The process of claim 18 or 20, further comprising thestep of winding around said fibers outer surface, at a preselectedposition along and orthogonal to the mandrel longitudinal axis, a carbonband of a preselected width comprising at least one electricallyconductive, continuous ribbon having a multiplicity of continuouslongitudinal carbon filaments impregnated with said fluidic admixture,thereby depositing a multiplicity of ribbon-layers forming acircumferential bead of a preselected height.
 25. The process of claim24 wherein said bead height is in a range from 0.187- to 0.125-inch. 26.The process of claim 18 or 20, wherein said chemically resistant resinis a halogenated epoxy vinyl ester resin.
 27. The process of claim 18 or20, wherein said chemically resistant resin is an unhalogenated epoxyvinyl ester resin.